diff --git a/src/mosquitto_broker.h b/src/mosquitto_broker.h
index 5f702289..105e8484 100644
--- a/src/mosquitto_broker.h
+++ b/src/mosquitto_broker.h
@@ -72,8 +72,7 @@ void mosquitto_log_printf(int level, const char *fmt, ...);
 /*
  * Function: mosquitto_client_address
  *
- * Retrieve the username associated with a client, or NULL if the client
- * provided no username.
+ * Retrieve the IP address of the client as a string.
  */
 const char *mosquitto_client_address(const struct mosquitto *client);
 
diff --git a/src/mosquitto_plugin.h b/src/mosquitto_plugin.h
index fed4de51..7dee2246 100644
--- a/src/mosquitto_plugin.h
+++ b/src/mosquitto_plugin.h
@@ -22,6 +22,7 @@ Contributors:
 #define MOSQ_ACL_NONE 0x00
 #define MOSQ_ACL_READ 0x01
 #define MOSQ_ACL_WRITE 0x02
+#define MOSQ_ACL_SUBSCRIBE 0x04
 
 #include <stdbool.h>